This invention relates to a technique that enables a computer to read data stored in a storage system.
In corporate activities, handling and utilizing a huge amount of business operation data has become essential. Therefore, the systems that multi-dimensionally analyze business operation data accumulated in massive amount in a database (hereinafter, referred to as “DB”) have widely been diffused. In this analysis processing, a database management system (hereinafter, referred to as “DBMS”) receives an inquiry and issues multiple data read requests to a storage system that stores the DB.
One of conventional technologies for executing multiple-data read processing efficiently is I/O scheduling. In I/O scheduling, a DBMS or similar application program (hereinafter, referred to as “AP”), or an operating system (hereinafter, referred to as “OS”), queues I/O requests. The AP or the OS identifies the logical block address (hereinafter, referred to as “LBA”) of the access destination for each of the plurality of queued I/O requests, and reallocates the output order in a manner that shortens the seek time or rotational latency of physical disk drives within the storage system (see pages 580 to 583 of the third edition of “Understanding the LINUX KERNEL” written by Daniel P. Bovet et al. and published by O'Reilly, November 2005).